# Resistive force question using T (tension)

1. Mar 25, 2013

### Siliconwombat

1. The problem statement, all variables and given/known data

A horse is pulling a canal boat using a rope at 12° to the direction of motion of the boat.
The tension in the rope is 1150 N.
(a) The canal boat is moving at a steady speed. Calculate the resistive force opposing
the boat’s forward motion.

2. Relevant equations

T = T cos θ

3. The attempt at a solution

Solution is given as:

= 1150 N x cos 12°
= 1125 N
Therefore resistive forces = 1125 N

However I've tried two different scientific calculators. The windows version comes out at 13800 and googles version comes out at 970.43

Am I using these tools incorrectly or are they flawed with calculations of this type?

Many thanks, its driving me crazy!

2. Mar 25, 2013

### ap123

Hi Siliconwombat

All it takes is a bit more care :-)

3. Mar 25, 2013

### Siliconwombat

Well i feel a little stupid on the first one!
However on the second which was using the windows calculator I cant see any way of identifying the 12 as degrees? any hints?

Think I'll have to buy a proper calculator again!

You'll have to bear with me I'm coming back to physics after a long break to try and improve myself!

4. Mar 25, 2013

### ap123

On my version of the Windows calculator, you can switch between "Standard" and "Scientific".
For the latter, there are radio buttons to choose from Degrees and Radians.

5. Mar 25, 2013

### Siliconwombat

Actually scratch that, it seems to dislike my use of cos fullstop. Think Ill stick to google fr now ;)

6. Mar 25, 2013

### Siliconwombat

Yeah I'm set on scientific and degrees but no matter which way I input the equation it only gives me 1150x12. It seems to ignore cos completely.

7. Mar 25, 2013

### Siliconwombat

nvm its the opposite way round so input as 12 cos *1150.